网页中js弹出模式窗口并传值的问题

<script type="text/javascript">
        //父窗体中打开模式窗口
        function SelectClient(ctlName) {
            var arr = showModalDialog('ClientList.aspx?TypeSelect=ClientType_qy&ClientOwner=' +154 + '&DefaultValue=' + document.getElementById(ctlName).value, '', 
'dialogWidth:600px; dialogHeight:450px; help: no; scroll: yes; status: no');
            if (arr != null) {
                document.getElementById(ctlName).value = arr;
            }
        }
        //子窗口返回值给父窗口的变量 ClientList.aspx中 
        <a onclick="javascript:window.returnValue='<%# Eval("ClientName")%>';window.close();"">
    </script>